The K-PH and K-T internal power supplies are powered by a single 9 Volt battery and provide powering for professional condenser microphones. The K-Tek K-PH internal phantom power supply provides regulated 48 Volts for professional phantom powered condenser microphones. The K-PH will supply power for even the most current demanding microphones for many hours and for several days for normal condenser microphones. A 15 db attenuator is provided and can be switched in by an internal DIP switch on the circuit board. The K-Tek K-T internal power supply provides regulated 12 Volts for "T" powered microphones. This unit also incorporates the switchable 15 db attenuator. It also has a power polarity reversing switch to accommodate any T powered microphones without changing phase. ***Having the condenser microphone power supply internal in the Boom Pole allows a completely "WIRELESS BOOM" with the addition of a standard, non modified compact wireless microphone transmitter inserted in the XLR connector. It also allows the use of mixers, or recording equipment that does not provide microphone power without extra equipment and cables. ***The electronic portion of the K-PH and K-T internal power supplies are manufactured by Denecke, Inc. ... the Dcode people. This insures a supply that will provide adequate power to achieve the full dynamic range and low noise characteristics that professional microphones are capable of. ***The K-PH and K-T internal power supplies will fit in any K-Tek microphone Boom Pole with the addition of an internal coiled cord.